Power drive for typewriting office machines



July l0, 1956 A. SALZBERGER POWER DRIVE FOR IYPEWRIIING OFFICE MACHINES Filed Jan. 14, 1953 United States Patent O POWER DRIVE FOR TYPEWRITING OFFICE MACHINES Andreas Salzberger, Frankfurt am Main, Germany, as-

slgnor to Torpedo-Werke Aktiengesellschaft, Frankfurt am Main, Germany Application January 14, 1953, Serial No. 331,189 Claims priority, application Germany January 25, 1952 5 Claims. (Cl. 197-17) ln power-driven olice machines, such as typewriters or book-keeping machines, the striking of the type levers is effected by swing levers, which are coupled to or act upon said type levers, which, whilst being mounted stationarily, upon the corresponding key lever being struck, are released so that a comb or cam surface provided on them bears against a continuously revolving driving cylinder, and after completion of the working cycle, return to the o position again. As a rule, the comb or cam surfaces are formed as discs or driver arms pivoted to the swing arms, which in the basic position of the swing arms, are held by springs or catch members at a distance from the driving cylinder, and are brought into a first position of bearing against the driving cylinder by the swing arms or control members inlluencing them. For adjusting the striking force, it is also known to align the swing arms by shifting the spindle carrying them into different positions relative to the driving cylinder, as has also been already proposed, by individual adjustment of the swing arms or the comb or cam discs carried by them, to adjust fthe striking force or the driving path of the various swing arms. It must here be borne in mind that in most constructions of the typewriting or bookkeeping machines here under consideration, the swing or working path of the intermediate levers diminishes towards the ends of the type lever segment on account of the increasing length of the intermediate levers towards said ends, so that steps must also be taken to vary correspondingly the driving path of the comb or cam arms. The use of differently formed comb or cam arms is undesirable for manufacturing reasons, so that, therefore, only the path of the different adjustment of said comb or cam arms, relatively to the swing arms, carrying them remains for the adjustment of the driving path. It has, therefore, already been proposed to associate with the comb or cam arms individually adjustable abutments, which without limiting the swinging path of the swing arms, lift the cam arms olf the driving cylinder according to differently adjustable driving paths, and also to make the mounting of the swing arms individually adjustable. This construction requires the provision of a comb plate for lifting the cam arms with individuallyadjustable comb teeth, as well as the use of individually adjustable bearing noses for each swing arm. In addition, this construction is unable to ensure a gentle termination of the driving path for the cam arms, since the latter are lifted ott the driving cylinder more or less suddenly.

The invention relates to a new construction of a device for adjusting the driving path of cam arms on the swing levers by the continuously revolving cylinder, which is substantially simple and which by adjustment according to the initial point of abutment for all swing arms, leads to the same uncoupling position and hence ensures uniform striking of the type.

According to the invention in a power drive for typewriting oce machines, in which the driving of the swlng arms, influencing the type levers, by the continuously revolving driving cylinder is elfected by means of cam arms ICC pivoted to the swing levers, which arms upon the striking of a key lever, are brought to bear with cam teeth against the driving cylinder by means of swing fingers influenced by said key lever, the driving cylinder is adjustably mounted relatively to the swing levers or cam arms carried by the latter, whilst said cam arms are adjustably mounted on the swing levers for regulating the point of application of the toothed arcuate member with the cylinder.

Preferably, the driving cylinder is mounted between swing arms of the machine frame, which are adjustable by means of eccentric discs of the frame, so that the cylinder can approach the cam teeth more or less, so as to regulate the driving friction between these parts during the working cycle, and hence determine the force of impact of the type characters.

The adjustment of the cam arms on the swing levers is preferably effected by means of rotatable and xable eccentric discs on the swing levers, said discs carrying the cam arms. For fixing, it is possible to use a ratchet disc rigidly connected to the eccentric discs, said ratchet discs being concentric with the pivot of the eccentric discs and being Xable by means of locking springs of the swing levers. Thus, the basic position of each cam arm relative to the swing lever carrying it and to the driving cylinder can be adjusted according to the necessary driving path, the initial engagement position being, however, regulated. Consequently, despite the different lengths of driving paths, driving is effected for all the cam arms to the end of the toothed arcuate member and hence uniform striking of the type characters.

The new construction is shown hereinafter with reference to the drawing, wherein Fig. l shows in vertical central section the parts of the driving mechanism, and

Fig. 2 a portion thereof on a larger scale.

The key levers 1 are mounted in known manner for swinging about a spindle 4 carried by a cross-piece Z of the machine frame 3 and are held in the basic position by spring 9. The key levers 1 are provided with upwardly projecting noses 6, a release lever 7 being associated with each nose 6. The release levers 7 are mounted for swinging movement about a carrying spindle 8 on the crosspiece 2. Each key lever 1 is coupled to the associated release lever 7 by a spring 9. These springs 9 hold the key lever system with the release levers 7 in the basic position.

The cross-piece 2 also carries arms 11 adapted to swing about a spindle 10, a key lever 1 being associated with each of said arms 11. Springs 5 engage the key levers 1 and the associated swing arms 11, so that said springs also hold the swing arms 11 in a basic position.

Each swing arm 11 is coupled to a type lever 13 by a connecting rod 12. The length of the swing arms 11 from the carrying spindle 10 to the hinge point of the connecting rod 12 increases from the middle of the ma chine to both sides thereof. Consequently, for constant path of swing of the type levers 13, which in otherwise known manner are adapted to swing out about a curved carrying spindle 14 of a receiving segment, the path of swing of the arms must diminish from the centre of the machine, outwards to both sides.

Pivoted to each swing arm 11 on a pin 15 is a ratchet disc 32, which receives a cam arm 16 on a circular disc 37 (Fig. 2) eccentric to it, said cam arm being provided at one end with an arcuate toothed part 17. The cam arms 16 are offset to one side in the middle and receive a spreader spring 19, one arm of which is held in a hole Z0 of the associated swing arm 11, whilst its other end bears against an abutment 22 on the cam arm 16 pro* vided by an olset 21.

Associated with the opposite end 16a of the cam arms 16, on an extension 11a of the swing arms 11 is a lever 23 which is slidable, by means of a pin 24, in a slot guide 25 of the extension 11a and is held by a spring 26, holding itby means of a bentgportion 18 against the extension 11a.- The portion Y18 vbear-s against 'the Vend `16u of the camarm `16 and holds the latter withthe arcuate toothed part 17,at a shortdistance'fromthe driving cylinder 27.

The drivingcylinder-27 is carried byits spindle 280m bearing plates 29, which are adapted to swing about carrying pivots 30 onthemaehine frame and are adjustable by means .of eccentricmollers 31. Thus, the position of the driving cylinder/27 can be adjusted relative to the cam arms 16.

vPassing through-the-hole 20tof theswing arms 11 is a spreader spring 33, one arm of which is anchored in a secondhole 34 of the swing armlfl, and the other arm is ysupported Vby a bentiportion resting on the ratchet disc 32. Thus, the basic position of the cam arms 16 can be adjusted relative to the swingarrns 11, and hencc'the initialv point of contact between the teeth 17 of the cam arms 16 and therdriving cylinder i217 can be adjusted.

Each lever 23 hasa nose 35 co-operating with a lifting part 36 of the associated release lever '7.

On the `striking of'a key'lever 1, the nose y6 thereof causes the associated releaselever -7 to swing out in an anti-clockwise direction, which lever, through the part 36, acts on thefnose 35 of the lever 23. The latter swings about the ,pin 24 likewise -in the-anti-clockwise direction, whereby the teeth 17 of the cam arm 16 come into engagement with the driving .cylinder 27. By means of the cylinder .27, revolving in the :anti-clockwise direction, the cam arm 16 is carried'upwardly. The swing arm 11 is thereby moved about its carrying spindle 10 into the position shown in chain linesin Fig. l, so that the type lever 13 is swung outward for striking.

Thefcurve of the teeth 17 -is .designed sothat, shortly before the type character strikes the platen, kthe run-oli end of the teeth 17.comesfree -from the drivingcylinder 27. Thus, by means ofthe momentum imparted to it, theitypelever 13 canproduce the-impression of the type character, whereuponfthefpartsfreturn to the starting position `under the actionof the spring k5. It the key lever 1 is -still heldin the depressed position, Vthe nose 35 of the lever 23 strikes against the lifting part 36, and is shifted to the right against the action of the spring 26 on the extension 11a, vwithoutthe teeth 17 coming to bear again on the Vdriving cylinder Vw27. Thus, for renewed striking of a character, the key lever 1 must rst be released, so that the part 36 can again come to bear over the nose 35 of the lever 23 which has returned to the basicposition.

.By turning the ratchet disc 3Z,-the basicposition of the cam ,arm 16 with the teeth -17 can be adjustedron Vthe swing arm 11 so that the teeth 17 do notrcome to bear against the-driving cylinder 27 with their commencement, but-only at a point situated more 'or less remote therefrom towards the end. By this means, the drivingpath of-the teeth 17 and hencethe .path of swing of-.each arm 11 can be regulated. vAt the same-time, however, each fi set of teeth 17 can be driven until the end rolls oit vthe cylinder 27.

By adjustment of the eccentric discs 31, the cylinder 27 can be caused to approach the'teeth 17 more or less, so as to be able to regulate the striking force for all type levers in common.

I ciaim:

l. A power drive fortypewriting oflice machines, comprising in combination,a frame, a plurality of key/levers pivotally mounted-on -said frame, said key levers having, respectively', projections, a plurality ofrelease levers arranged for cooperation, respectively, with said projections of said'keytlevera -a plurality of Sli'dable'levers arranged for cooperation, respectively, with said release levers, a plurality of swing levers adapted to cooperate, respectively, with-saidslidable levers, a plurality of cam arms pivotally mounted and positionally adjustable, respectively, on said swing levers, a driving-cylinder rotatably mounted von said frame, said .cam arms having, respectively, arcuate toothed .parts adapted to engage said'driving cylinder when said key lever corresponding to-saidtoothed partis depressed, theipivotal mountings of said cam arms-being adjustable throughout Van uninterrupted-,adjustment range with respect to Said swing levers and said driving cylinder so as to rotate said toothed parts, respectively, through adjustable angles, said toothed parts engaging, lrespectively, said drivingfcylinder with substan- -tiallytthe lower half of'their arcuate portions, and a type leveroperatively: connected to each swing lever, the swing levers beingrotated .by the-engagement .of the cam arms with {the driving cylinder and causing the type levers to beoperativelypivoted.

2. flnlapoweidrive according to claim il, bearing plates carrying the driving cylinder, Asaid bearing plates being pivotable about their ends remote -from the cylinder to allow adjustment of said cylinder relative to the toothed partsof the cam'arms.

3. vIn fa :power drive according to claim 1, a helical spring mounted initension between eachzof the key levers and the corresponding release lever said 4spring urging said leversfinto the inoperativeposition.

4. In Ia power drive according to claim `1, eccentric discs pivotable aboutpivotal .axes on said swing levers, saidcam-arrns being mounted on said discs, and said-discs permitting individual adjustment of the-cam arms relative'to-the drivinglcylinder.

5. fInafpowerdrive .according to-claim 4, ratchet discs mounted eo-aXiallywith the pivotal axes of the eccentric discs-on Ethe swing levers, and locking springs engaging the =teeth of said -ratchet discs and maintaining the cam leversin adjustedposition.

References Cited in the le of this `patent 'UNITED STATES PATENTS 1,963,285 vWoodward June '19, 1934 2,528,450 Petz Oct. 31, 1950 2,620,056 -Kupper Dec. 2, 1952 2,717,685 Buhler Sept, 13, 1955 

